Dishwashers, such as household dishwashers, conventionally use condensation drying to dry the items washed. To this end, in conventional household dishwashers, for example, the wash liquid; i.e., the water contained in the dishwasher, the washing chamber thereabove, and the items to be washed are heated to temperatures of between about 65° C. (degrees Celsius) and 70° C. at the end of the wash cycle after the last water-supplying cycle step, typically the final rinse step. The water vapor given off by the tableware condenses on condensation surfaces, mostly on the inner walls of the washing chamber, and flows into the wash liquid. This method requires a large amount of energy, which is released into the environment and cannot be used further in the process.
Moreover, from German Publication DE 10 2008 038 504 A1, for example, dishwashers having sorption drying devices are known in which air circulating within the washing chamber is passed through a drying agent (also called sorption agent) contained in the sorption drying device and dehumidified. Due to the removal of moisture from the air, the items to be washed can be dried more quickly at lower temperatures, which allows energy savings during the drying process as compared to condensation drying. During a subsequent wash cycle, the moisture taken up by the sorption agent during drying is removed from the sorption drying device during a desorption process and delivered into the washing chamber, and thus returned into the wash liquid. The desorption process requires input of energy in the form of heat. However, the energy input is less than the energy that is saved during the drying process, compared to condensation drying. Consequently, sorption drying allows for a net energy savings compared to condensation drying.
German Publication DE 10 2008 043 576 A1 describes a method for operating a dishwasher having a sorption drying device, where the point in time at which the desorption process is to be carried out is determined based on parameters such as, for example, air temperature and/or water inlet temperature. The method described allows the moisture previously taken up in the sorption drying device to be desorbed as completely and quickly as possible with as little additional energy expenditure as possible.